1. Field of the Invention
The present invention relates to a string tightening device for a string instrument with at least one string which can be tightened by a tuning screw operable from one side of the string instrument, which is freely accessible at least during play and a moving nut for the purpose of tightening the string that is guided in a torsion-resistant manner on the tuning screw and may be shifted by rotating the tuning screw. The string is connected to the moving nut, and the connecting point of the string to the moving nut and the tuning screw is staggered, as viewed in the shifting direction of the moving nut.
2. Discussion of Background Information
A string tightening device for a string instrument of the type mentioned at the outset is known from U.S. Pat. No. 2,813,448. The present application is intended for string instruments, such as, in particular, guitars and guitar-like musical instruments. In the string tightening device according to U.S. Pat. No. 2,813,448, two plates are fastened to the body of the string instrument, parallel to the level of the tightened strings. The tuning screws, fixed to be immobile in the longitudinal direction, and the moving nut, shiftable on the tuning screws during rotation of the tuning screw are provided and, between these plates, the tuning screws can be activated from the side of the string instrument facing the tightened strings. The ends of the strings are staggered next to the tuning screws at the corresponding moving nuts. With their two end regions, the tuning screws are positioned on the plates to be immobile in the longitudinal direction. One disadvantage of this arrangement is that, in order to avoid the plates bending during tightening of the strings, the parallel plates must be embodied in a comparatively voluminous manner. In the longitudinal direction of the tuning screw, the moving nuts are guided only by guiding rods in this arrangement. The guiding rods must be fastened to the parallel plates during a special process and must be embodied as being comparatively strong and voluminous, because they are subjected to a considerable amount of stress. This arrangement requires a relatively large amount of space affecting, the overall dimensions of the string instrument and resulting in economical disadvantages. In summary, it can be stated that this arrangement requires an expensive installation, a relatively large amount of space, and is economically disadvantageous.
U.S. Pat. No. 3,830,132 shows another string tightening device having a tuning screw positioned concentrically to it, operating the moving nut that supports the end of the string. This tuning screw can only be operated from the side of the musical instrument next to the body and facing away from the tightened strings, which is troublesome for the musician, in particular when simultaneously plucking the strings. Additionally, this string tightening device is comparatively long in relation to the string tightening lift causing the space required for the guitar body to be correspondingly large.
The present invention provides a string tightening device of the type mentioned at the outset that has comparatively small dimensions, in particular with a short assembly length in relation to the string tightening lift, a simple and inexpensively produced guidance of the moving nut, and can be easy to incorporate into the body of the string instrument without any considerable weakening of the body and without any particular reinforcements, and allowing a compact construction of the string instrument.
Accordingly, the present invention provides two guide surfaces facing one another for guiding the moving nut in the direction of the tuning screw, which guide surfaces are connected to the body of the string instrument in a form-fitting manner and which compensate the stress caused by the tightened strings on the moving nut mounted for that purpose in two opposing directions. This string tightening device formed by a tuning screw and by a moving nut guided thereon in a displaceable manner is provided with comparatively small dimensions. The simple guidance of the moving nut in two parallel guide surfaces fixed to the body of the string instrument is space-saving and avoids bulky guidance devices that can be installed only with difficulty. The tightening screw is freely accessible during the tightening of the string. A reinforcement of the body of the string instrument positioned around the string tightening device is not necessary. A compact design of the string instrument is possible. Therefore, this string tightening device can be used for so-called travel guitars as well.
Advantageously, the guiding surfaces are separately positioned in a tubular case for each separate moving nut, with the tuning screw having a symmetrical axis outside of the bisecting line of the case and the moving nut being shiftable thereon in order to tighten the assigned string provided in each tubular case. This arrangement can be assembled independently of the distance between the separate strings in various string instruments. Due to the separate string tightening devices being assembled separately from one another in the body of the musical instrument, a possible interaction of the separate strings and the string tightening devices is avoided.
The case is advantageously provided with a circular cross section with the moving nut being guided in a torsion-free manner. If the cross section of the case is circular, it can be fastened in a single bore in the body of the musical instrument.
The tubular case can be provided with a cross section other than a circular one as well, with the moving nut being guided in a torsion-free manner. Such a cross section of the tubular case ensures the torsion-free guidance of the moving nut.
The tubular case can be fastened in the body of the string instrument by means of a rod that can penetrate the case and the adjacent body of the string instrument as well. The rod locks the tubular case in the body of the string instrument in an easy fashion.
Advantageously, the tapered end of the tuning screw inserts through the base cover of the case and contacts from the inside with a shoulder and is fixed therein to be immobile in the longitudinal direction by a fixing element mounted to the part of the tuning screw penetrating the base cover. It is simplest for the tuning screw to be fixed to the base cover of the case, preventing a longitudinal shifting.
Advantageously for all moving nuts positioned parallel next to one another, the guide surfaces are positioned on the inner sides of the two parallel side walls facing one another on the U-shaped profiled bar fastened on the body of the string instrument. The entire string tightening device provided with the guide surfaces can be prefabricated and built into the body of the string instrument in a simple fashion.
The guide surfaces for all moving nuts positioned next to one another can be positioned on the inner sides of two parallel and opposing side walls of a support arrangement that is provided on the body of a string instrument and that has a closed cross sectional form. A predominantly polygonal support arrangement provided with a closed shape grants the body of the string instrument a particularly good stability and supports the guide surfaces for the moving nuts as well. The support of the tuning screw in the support arrangement can easily be accomplished as well. Here, the support arrangement can be embodied in one piece or can be of several partial elements mounted on the body of the string instrument. The guide surfaces for all moving nuts positioned next to one another can also be provided on two parallel guidance plates, positioned opposite one another in the body of the string instrument, separately mounted directly to the body. These guide surfaces are integrated into the body of the musical instrument, thus facilitating the production of the musical instrument.
The moving nut can also be provided with a bore for fastening the end of the string, with the end of the string having a knot that cannot be pulled through the bore. The string is securely fastened to the moving nut by a single knot.
In order to fasten the end of the string the moving nut can be provided with a self-clamping fastening device having a pivotal lever. The self-clamping fastening of the end of the string onto the moving nut offers a simplified installation of the string.
Advantageously, the tapered end of the tuning screw penetrates a base cover of the support arrangement and contacts it from the inside at a shoulder and is fastened there to be immobile in the longitudinal direction by a fastening element mounted to the part of the tuning screw penetrating the base cover. In the simplest case, the tuning screw is held in the base cover of the case to prevent a longitudinal shifting.
Advantageously, a string guided crosswise through the case and fastened with both ends at the body of the string instrument is pulled through a traverse bore provided in the end region of the moving nut that can be ejected from the case and reinserted into the case and this string can be inserted into the case by the moving nut during tightening of the string. This arrangement is particularly suitable for a string instrument, in particular a guitar, in which the string tightening is provided from the cover side, freely accessible during play or tightening, positioned perpendicular to the longitudinal direction of the tightened string with the string tightening being opposite to the head of the string instrument. The non-centric positioning of the bisecting axis of the tuning screw in the case allows the use of the full stroke of the moving nut for tightening the string.
Advantageously, a common cover plate is provided for all tuning screws covering the string tightening device, with the cover plate being provided with an operational opening for each tuning screw. This cover improves the aesthetic impression of the musical instrument. Simultaneously, the cover plate can be provided with a guidance support acting at least perpendicularly to the longitudinal direction of the tightened strings for one end of each tuning screw. This guidance support is necessary for arrangements in which the guide surfaces for the moving nut guide only in the longitudinal direction of the tightened strings.
A tubular case can be sealed with a cover plate at the end facing the operating points of the tuning screw with the tuning screw penetrating the cover plate and a pressure coil being provided between the cover plate and the moving nut supported thereby and-the string being fed to the moving nut from the end of the case opposite to the cover plate. This arrangement is particularly suitable for guitars with the operation of the tuning screw being desired on the end of the guitar opposite to the guitar neck. The feeding of the string from the end of the case opposite to the cover plate allows the fastening of the string to the moving nut in an easily accessible point.
The present invention is directed to a string tightening device for a string instrument having at least one string. The string tightening device includes a tuning screw arranged to be operable from a freely accessible side of the string instrument at least during play, and at least two opposing guide surfaces structured and arranged to be coupled to a body of the string instrument. A moving nut is coupled to the tuning screw and is guided between the at least two opposing guide surfaces to adjust a tension in the strings, and the moving nut includes a string connection point which is offset from the tuning screw.
In accordance with a feature of the invention, the moving nut can be guided between the at least two opposing guide surfaces in a substantially torsion-free manner.
According to another feature of the present invention, the moving nut may be movable in a direction parallel to a longitudinal axis of the tuning screw. The at least two opposing guide surfaces may be coupled to the body in a form fitting manner to compensate for pressure created by tightening the string in opposing directions in the longitudinal axis direction.
The string tightening device may also include a plurality of moving nuts and a plurality of at least two opposing guide surfaces, such that each of the plurality of at least two opposing guide surfaces are associated with one of the plurality of moving nuts. A plurality of tubular cases can be fastened to the body, so that each of the plurality of tubular cases can be arranged to contain one of the at least two opposing guide surfaces and the associated moving nut. A plurality of tuning screws can also be provided so that each of the tubular cases include one of the plurality of tuning screws. In each of the plurality of tubular cases, the tuning screw may have a symmetrical axis offset from a bisecting line of the case and the moving nut can be movable along the tuning screw to adjust string tension.
At least one of the plurality of tubular cases can include a circular cross-section. Alternatively or additionally, at least one of the plurality of tubular cases may include a non-circular cross-section.
Further, a rod can be arranged to fix at least one of the plurality of tubular cases the body. The rod may be arranged to extend from within the case into the body. The tubular case may include a base cover and the tuning screw may include a tapering end arranged to penetrate through the base cover. A fixing element can be couplable to an end of the tapering end extending through the base cover. The tapering end can form a shoulder arranged to contact an inside surface of the base cover.
Moreover, the plurality of at least two opposing guide surfaces for all of the plurality of moving nuts can form parallel side walls of a U-shaped support arrangement mounted to the body.
Still further, the plurality of at least two opposing guide surfaces for all of the plurality of moving nuts can form parallel side walls of a support arrangement having a closed cross sectional shape mounted to the body. The support arrangement may be a one piece element. Alternatively, the support arrangement can include several partial elements mounted to the body.
In accordance with still another feature of the present invention, the moving nut may include a bore arranged to receive an end of the string from outside of the body and to selectively prevent removal of the end of the string from the body.
The string tightening device may further include a self-clamping device coupled to the moving nut for fastening an end of the string to the moving nut. The self-clamping fixing device can include a pivotal lever.
Moreover, the string can have two ends which are fixed to the body and the string may be guided through a case in a direction substantially perpendicular to an axial length of the case. The moving nut may be arranged for movement along the axial length of the case, and the moving nut can include an end region which is selectively within the case or outside of the case. The end region can include a bore extending substantially perpendicular to the axial length of the case.
The string tightening device can further include a cover plate provided for all tuning screws. The cover plate may include operating openings for each tuning screw. The cover plate may provide guidance support acting at least substantially perpendicular to a longitudinal direction of the tensioned string for the end of each tuning screw.
In accordance with a further feature of the instant invention, a tubular case and a cover plate can be included. The cover plate can be arranged to close one end of the tubular case, and the tuning screw may be arranged to penetrate the cover plate and a pressure spring can be provided between the cover plate and the moving nut. The string can be fed to the moving nut from an end of the case opposite the cover plate.
The present invention is directed to an apparatus for adjusting a tension in a string for a string instrument. The apparatus includes at least one tuning screw arranged to be operable from a freely accessible side of the string instrument at least during play, and at least one moving nut arrange to move along an axis of the at least one tuning screw. The moving nut may include a string connection point which is offset from the tuning screw axis.
According to a feature of the invention, a guiding device can be arranged to guide, substantially torsionally free, the moving nut along the tuning screw axis.
In accordance with yet another feature of the present invention, a support element can be included to which the tuning screw is coupled to prevent axial movement of the tuning screw.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.